1. Field of the Invention
The invention relates generally to the field of electrical connectors. More particularly, the invention relates to electrical connectors used to terminate electrical cables used with seismic data acquisition systems.
2. Background Art
Seismic data acquisition systems known in the art include various types of seismic sensors, such as single component geophones, multi-component geophones, accelerometers, and other sensing devices, disposed at spaced apart positions along a cable. The cable typically includes a number of insulated electrical conductors that carry electrical signals from the seismic sensors to various signal processing and telemetry devices that may be interconnected at selected positions along such cables. The electrical conductors may also carry electrical power to the signal processing and telemetry devices.
In some seismic data acquisition systems, the signal processing and telemetry devices may be disposed in modules that are adapted to be coupled to electrical connectors. Such electrical connectors are typically affixed to the ends of sections of such cables. Typical seismic data acquisition systems are designed to enable a number of different user selected configurations of such cables and signal processing/telemetry modules by appropriate coupling of cable sections to the processing/telemetry modules.
Cable sections typically terminate in electrical connectors that include electrical contacts for providing an electrically conductive path from the conductors in the cables to corresponding, mating contacts in the modules and ultimately to various circuits in the modules. The electrical connectors may also include various devices to transmit axial stress from the cable sections to the modules. Finally, the electrical connectors may include various devices to exclude fluid from entering into the modules or into the cable sections when the connectors are mated to the modules. Fluid excluding devices can provide the seismic data acquisition system with the capacity to be used on land in relatively humid environments, and with appropriate configurations of modules, to be used in relatively shallow water.
The electrical connectors are typically made from a molded housing or shell, which may include electrical contact pins molded into an exterior connection portion thereof for mating to a corresponding connector on the module. The connectors known in the art also include some type of device to couple a strength member in the cable to a mechanical load bearing portion of the connector. Finally, the connectors known in the art include some form of cover or other barrier to enclose an interior chamber inside the shell. Electrical connections are typically made within this interior chamber between the conductors in the cable and the electrical contact pins molded into the connector housing. The chamber is typically enclosed by the cover after electrical connection is made between the conductors and the contact pins, however, upon enclosure, the chamber remains substantially filled with air.
It has been observed that the existence of the air-filled chamber makes connectors known in the art susceptible to the need for frequent repair, because the cover may be susceptible to leakage. Leakage may enable water intrusion into the chamber if the data acquisition system is used in water, or moisture intrusion and condensation if the system is used in humid environments on land. In either case, moisture inside the chamber may cause failure of the insulation between the conductors, thus causing disruption of operation of the seismic data acquisition system. Still further, water intrusion into the connector chamber, such as may occur if the connector is submerged and becomes uncoupled from a module, may result in water intrusion into the interior of the cable itself, making it necessary to replace the intruded cable.
It is desirable to have a connector for use with seismic data acquisition systems that is better suited to exclude moisture from the interior of the connector, and to exclude water from entering the cable in the event of failure of the connector to seal or remain engaged with a mating housing.